Authors' response to the letter to the Editors by Professor M. T. Cibulka: a critical interpretation of sacroiliac joint movement studies (original) (raw)

Three-Dimensional Movements of the Sacroiliac Joint: A Systematic Review of the Literature and Assessment of Clinical Utility

Journal of Manual & Manipulative Therapy, 2008

T he sacroiliac joints (SIJ) are multi-planar, simultaneously rotating and translating along three axes of motion through an origin point that lies midway between the left and right posterior superior iliac spines (PSIS) 1 . The sacral X-axis (transverse axis) courses mediolateral through the left and right PSIS, with corresponding sacral rotation occurring in the sagittal plane. The sacral Y-axis (longitudinal axis), accounts for sacral rotation in the horizontal plane, whereas the Z-axis (sagittal axis), courses anterior-posterior midway between the anterior superior iliac spines (ASIS) and accounts for sacral rotation in the coronal plane 2 . The previously described motion about the X, Y, and Z axes constitutes a Cartesian coordinate system and is used by investigators to account for the 3-D sacral motion at the SIJs in reference to a fi xed pelvis 2-8 with occasional alterations of the X and Z axes 1,9 .

The influence of hip abduction and external rotation on sacroiliac motion

Manual Therapy, 2009

Although the sacroiliac joint (SIJ) is conventionally accepted as a sagittal joint with little mobility in other planes, recent research has shown evidence for reduced hip abduction and axial rotation in patients with sacroiliac pain. A sample of healthy individuals was investigated to determine whether innominate motion about the sacroiliac joint can be predicted from abduction and external rotation displacement of the femur. The motion of the innominate and femur were tracked as the hip was passively rotated by standardized increments of 10 into (1) abduction; (2) external rotation; and (3) a combination of external rotation and abduction. Although sagittal and transverse plane innominate motion both increased significantly as the hip was rotated further into either abduction or external rotation, external rotation was the strongest predictor of change in innominate angle. A combination of external rotation and abduction led to greater increases in these innominate angles at a smaller degree of hip rotation. The results support the use of abduction and external rotation hip displacements (both singularly and in combination) for assessing SIJ mobility at least in the axes investigated. Further research that investigates the use of these tests in people with SIJ disorders is warranted.

A Systematic Review of the Normal Sacroiliac Joint Anatomy and Adjacent Tissues for Pain Physicians

Pain Physician

Background: The sacroiliac joint (SIJ) forms a complex joint and has shown to be underappreciated in its involvement with lower back pain. Research efforts have intensified on SIJ anatomy and biomechanics because of its predisposing position to pain and dysfunction in individuals suffering from lower back discomfort. Previous work has focused on SIJ anatomy including bone and joint structure, innervation, as well as biomechanics and the treatment of SIJ pain. However, to date, no review exists describing the range of ‘normal’ anatomic features of the SIJ. Objectives: To describe the normal appearance of the SIJ and adjacent tissues, as opposed to ‘abnormal’ conditions involving SIJ morphology. It will also identify key areas that require further study because of lacking information or disagreement. Study Design: A systematic literature review. Setting: The research took place at the University of Otago, New Zealand. All published research on ‘normal SIJ anatomy’ available from MEDLI...

Joint coordinate system for biomechanical analysis of the sacroiliac joint

Journal of Orthopaedic Research, 2019

ABSTRACTSacroiliac joint (SIJ) biomechanics have been described in both in vitro and in vivo studies. A standard for joint coordinate systems has been created by the International Society of Biomechanics for most of the joints in the human body. However, a standardized joint coordinate system for sacroiliac joint motion analysis is currently still lacking. This impedes the comparison across studies and hinders communication among scientists and clinicians. As SIJ motion is reported to be quite limited, a proper standardization and reproducibility of this procedure is essential for the interpretation of future biomechanical SIJ studies. This paper proposes a joint coordinate system for the analysis of sacroiliac joint motion, based on the procedure developed by Grood and Suntay, using semi‐automated anatomical landmarks on 3D joint surfaces. This coordinate system offers high inter‐rater reliability and aspires to a more intuitive representation of biomechanical data, as it is aligne...

Intra-observer reliability in three-dimensional kinematic analysis of sacroiliac joint mobility

Journal of Physical Therapy Science, 2015

Physical therapists, osteopathic practitioners, and chiropractors often perform manual tests to evaluate sacroiliac joint (SIJ) mobility. However, the available evidence demonstrates an absence of reliability in these tests and in investigations with kinematic analysis. The aim of this study was to verify the three-dimensional kinematic reliability in SIJ movement measurements. [Subjects] This cross-sectional study analyzed 24 healthy males, aged between 18 and 35 years. [Methods] Three-dimensional kinematic analysis was performed for measurements of posterior superior iliac displacement and greater trochanter (femur) displacement during hip flexion movement in an orthostatic position. The distance variations were measured from a reference point in 3 blocks. The intra-observer reliability was compared with the mean of three 3 blocks using the interclass correlation coefficient (ICC) and a 99% significance level. [Results] The measurements indicated a strong correlation among blocks: ICC = 0.94 for right side SIJ and ICC = 0.91 for left side SIJ. The mean displacement between the reference points was 7.7 mm on the right side and 8.5 mm on the left side. [Conclusion] Our results indicate that three-dimensional kinematic analysis can be used for SIJ mobility analyses. New studies should be performed for subjects with SIJ dysfunction to verify the effectiveness of this method.

Mobility in the sacroiliac joints in the elderly: a kinematic and radiological study

Clinical Biomechanics, 1992

Movement in eight sacroiliac joints was measured in preparations of embalmed elderly humans and compared with radiological findings. For the biomechanica1 part of the study the connections between sacrum and fifth lumbar vertebra were spared, as were the surrounding ligaments. The pelvis-spine preparation was fixed at the fifth lumbar vertebra. To induce movement, forces were directed at the acetabula. With digital displacement meters rotation was measured between the sacral and iliac part of the sacroiliac joint. In the sagittal plane both ventral rotation (as part of nutation) and dorsal rotation (as part of contranutation) could be demonstrated. Most sacroiliac joints were mobile, allowing a total rotation of up to 4". Significant intraindividual differences in mobility occurred. One sacroiliac joint without mobility showed radiographically pronounced arthrosis. The impact of the findings on kinematic chain and clinical diagnosis is discussed. Relevante In the literature no data are available on the radiographic appearance of biomechanically studied sacroiliac joints. In the present study a biomechanica1 and radiological approach has been combined. The study emphasizes the clinical importante of intraindividual sacroiliac differences as well as the need for a thorough integration of pelvic and lumbar kinematics.

Effect of Sacropelvic Hardware on Axis and Center of Rotation of the Sacroiliac Joint: A Finite Element Study

The International Journal of Spine Surgery, 2022

Background: The sacroiliac joint (SIJ) transfers the load of the upper body to the lower extremities while allowing a variable physiological movement among individuals. The axis of rotation (AoR) and center of rotation (CoR) of the SIJ can be evaluated to analyze the stability of the SIJ, including when the sacrum is fixed. The purpose of this study was to determine how load intensity affects the SIJ for the intact model and to characterize how sacropelvic fixation performed with different techniques affects this joint. Methods: Five T10-pelvis models were used: (1) intact model; (2) pedicle screws and rods in T10-S1; (3)pedicle screws and rods in T10-S1, and bilateral S2 alar-iliac screws (S2AI); (4) pedicle screws and rods in T10-S1, bilateral S2AI screws, and triangular implants inserted bilaterally in a sacral alar-iliac trajectory ; and (5) pedicle screws and rods in T10-S1, bilateral S2AI screws, and 2 bilateral triangular implants inserted in a lateral trajectory. Outputs of these models under flexion-extension were compared: AoR and CoR of the SIJ at incremental steps from 0 to 7.5 Nm for the intact model and AoR and CoR of the SIJ for the instrumented models at 7.5 Nm. Results: The intact model was validated against an in vivo study by comparing range of motion and displacement of the sacrum. Increasing the load intensity for the intact model led to an increase of the rotation of the sacrum but did not change the CoR. Comparison among the instrumented models showed that sacropelvic fixation techniques reduced the rotation of the sacrum and stabilized the SIJ, in particular with triangular implants. Conclusion: The study outcomes suggest that increasing load intensity increases the rotation of the sacrum but does not influence the CoR, and use of sacropelvic fixation increases the stability of the SIJ, especially when triangular implants are employed. Clinical Relevance: The choice of the instrumentation strategy for sacropelvic fixation affects the stability of the construct in terms of both range of motion and axes of rotation, with direct consequences on the risk of failure and mobilization. Clinical studies should be performed to confirm these biomechanical findings.

Load-displacement behavior of sacroiliac joints

Journal of Orthopaedic Research, 1987

We measured the load-displacement behavior of both single and paired sacroiliac (SI) joints in fresh cadaver specimens obtained from eight adults between the ages of 59 and 74 years. With both ilia fixed, static test loads were applied to the center of the sacrum along and about axes parallel and normal to the superior S 1 endplate. Test forces up to 294 N were applied in the superior, inferior, anterior, posterior, and lateral directions. Moments up to 42 N-m were applied in flexion, extension, lateral bending, and axial torsion. Displacements of the center of the sacrum were measured 60 s after each load increment was applied, using dial gauges and an optical lever system. The tests were then repeated with only one ilium fixed. Finally, the three-dimensional location and overall geometry of each SI joint were measured. For an isolated left joint at the maximum test loads, the mean (SD) sacral displacements in the direction of the force ranged from 0.76 mm (1.41) in the medial to 2.74 mm (1.07) in the anterior direction. The mean rotations in the directions of the moments ranged from 1.40" (0.71) in right lateral bending to 6.21" (3.29) in clockwise axial torsion viewed from above. We also examined load-displacement behavior under larger loads. Single sacroiliac joints resisted loads from 500 to 1440 N, and from 42 to 160 N-m without overt failure.

Biomechanics of unilateral and bilateral sacroiliac joint stabilization: laboratory investigation

Journal of neurosurgery, 2018

OBJECTIVE Bilateral symptoms have been reported in 8%-35% of patients with sacroiliac (SI) joint dysfunction. Stabilization of a single SI joint may significantly alter the stresses on the contralateral SI joint. If the contralateral SI joint stresses are significantly increased, degeneration may occur; alternatively, if the stresses are significantly reduced, bilateral stabilization may be unnecessary for patients with bilateral symptoms. The biomechanical effects of 1) unilateral stabilization on the contralateral SI joint and 2) bilateral stabilization on both SI joints are currently unknown. The objectives of this study were to characterize bilateral SI joint range of motion (ROM) and evaluate and compare the biomechanical effects of unilateral and bilateral implant placement for SI joint fusion. METHODS A lumbopelvic model (L5-pelvis) was used to test the ROM of both SI joints in 8 cadavers. A single-leg stance setup was used to load the lumbar spine and measure the ROM of each SI joint in flexion-extension, lateral bending, and axial rotation. Both joints were tested 1) while intact, 2) after unilateral stabilization, and 3) after bilateral stabilization. Stabilization consisted of lateral transiliac placement of 3 triangular titanium plasma-sprayed (TPS) implants. RESULTS Intact testing showed that during single-leg stance the contralateral SI joint had less ROM in flexionextension (27%), lateral bending (32%), and axial rotation (69%) than the loaded joint. Unilateral stabilization resulted in significant reduction of flexion-extension ROM (46%) on the treated side; no significant ROM changes were observed for the nontreated side. Bilateral stabilization resulted in significant reduction of flexion-extension ROM of the primary (45%) and secondary (75%) SI joints. CONCLUSIONS This study demonstrated that during single-leg loading the ROMs for the stance (loaded) and swing (unloaded) SI joints are significantly different. Unilateral stabilization for SI joint dysfunction significantly reduces the ROM of the treated side, but does not significantly reduce the ROM of the nontreated contralateral SI joint. Bilateral stabilization is necessary to significantly reduce the ROM for both SI joints.

A posterior approach for inspection of reduction of sacroiliac joint disruption

Surgical and Radiologic Anatomy, 2000

This anatomic study was undertaken to describe a new posterior approach enabling direct inspection of reduction of sacroiliac joint disruption (SIJD), and guidance of iliosacral screw placement. The reduction of SIJD is usually monitored by inspection of the opposing sacrum and ilium at the posterior margin of the greater sciatic notch and there is a relative lack of information concerning inspection of reduction of SIJD from the postemsuperior aspect of the sacroiliac joint surface. Ten cadavers were dissected to determine the possibility of inspecting reduction of SIJD from the posterosuperior aspect of the sacroiliac joint by means of a posterior approach which passed immediately lateral to the deep back muscles and the fifth lumbar transverse process. The results indicated that the posterosuperior aspect of the sacroiliac joint surface and sacral ala can be directly palpated or visualised. This approach facilitates improved access for inspection of reduction of SIJD and guidance of iliosacral screw placement.